diff --git a/aegisub/libaegisub/include/libaegisub/util.h b/aegisub/libaegisub/include/libaegisub/util.h
index 6288a578f..bca64c108 100644
--- a/aegisub/libaegisub/include/libaegisub/util.h
+++ b/aegisub/libaegisub/include/libaegisub/util.h
@@ -21,6 +21,7 @@
 #include <algorithm>
 #include <cstdint>
 #include <string>
+#include <memory>
 
 struct tm;